Currently, the IMS network may provide Session Initiation Protocol (SIP)-based RBT services and presence services.
The presence services provide current presence information of a presence service subscriber. The presence information may include multiple status information, including reachability, current communication mode, availability, mood, and location of a User Equipment (UE). A presence server stores and manages the presence information of the presence service subscriber. The presence information, such as location information, may be manually modified by the subscriber or updated by related network devices. The modified presence information may be notified by the presence server to presence service subscribers that subscribe to the presence information.
The RBT service allows mobile subscribers and fixed-line subscribers to customize a special RBT to replace a traditional one and play the RBT to calling users. In networks provided by different operators, the RBT service may be identified by different names.
The RBT customized by a subscriber may be an audio clip including music or pre-recorded voice information, or multimedia information including video, audio or other media. The RBT service subscriber may select an RBT file provided by a service provider or an operator through a Portal on the Internet, or upload an RBT file that the subscriber edits to the Internet, or copy RBTs of other subscribers for personal use with copyright permission. The RBT service subscriber may also set different policies for playing these RBT files. For example, the subscriber may play different RBT files in different time segments or play different RBT files to different calling users. When a calling user calls a subscriber who already applies for the RBT service, the calling user may see or hear the RBT file information selected by the subscriber, not the traditional tone.
Currently, the RBT playing policies set by RBT service subscribers are fixed in a fixed network or mobile network. A fixed RBT file is played to a fixed calling user or in a fixed time segment, or a group of fixed RBT files is played in random or cyclic mode. Even if a subscriber sets an RBT playing policy according to his or her presence status, the RBT file may not be determined according to the current presence status of the subscriber when the subscriber is called, because a Multimedia Ring Back Tone Application Server (MRBT AS) in the network may not obtain the current presence information of the called user. Thus, what the calling user obtains is the RBT information that is set by the called user for the particular time segment or the calling user, and not for the RBT information that is set according to the current presence status of the called user.